Nasal pillows for a patient interface

ABSTRACT

A nasal pillow section for use as part of an apparatus for providing a stream of gases to a user, the pillow section in use located in front of the upper lip and below the nostrils of a user, the pillow section comprising a pillow gasket having a gases aperture which receives a stream of gases in use, and nasal pillows fluidically connected to the pillow gasket which are adapted to substantially seal against the nostrils of a user in use, so that substantially the whole of the stream of gases entering the gasket through the aperture passes into the nasal pillows from the pillow gasket and is delivered to the user, the lower inner surface of the pillow gasket shaped so that in use contact between the upper lip of a user and the pillow gasket is minimised.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to nasal pillows for use with a patientinterface that provides a supply of pressurised gas to a recipient viathe nasal passages. The invention also relates to a patient interfacewhich includes nasal pillows, and which may also include associatedelements such as headgear. The invention also relates to a system forproviding a heated, humidified stream of gases to a user via a patientinterface which is included as part of the system and which includesnasal pillows.

Description of the Related Art

The prior art includes a wide variety of interfaces for supplying gasesto a recipient. The following are examples.

The prior art includes a nasal mask that can be used for supplying gasesto a recipient. The nasal mask includes a perimeter seal that sealsacross, down each cheek alongside the nose and along the surface of theupper lip. The entire enclosed space is pressurised and the recipientmay inhale the pressurised gas from the enclosed space. An example isthe Flexifit 405 nasal mask sold by Fisher & Paykel Healthcare.

The prior art also includes a full face mask. The full face maskincludes a perimeter seal that extends across the bridge of the nosedownward along each cheek beside the nose to the jaw and along the jawbelow the lower lip. The perimeter thereby encloses both the nose andmouth. The entire space within the mask frame is pressurised. Therecipient may breathe the pressurised gas from the space through eitherthe nose or mouth. An example is the Flexifit 431 interface sold byFisher & Paykel Healthcare.

The prior art further includes an oral interface including an oralappliance that fits within the user's mouth. An example is the Fisher &Paykel Healthcare Oracle interface.

The prior art still further includes a nasal pillows interface in whichheadgear retains a soft plenum in the vicinity of the user's nose. Apair of flexible protrusions engage against the nares of the recipient.Typically, the protrusions are able to axially compress and have alateral freedom of movement relative to the supporting cushion. Examplesare the ResMed Mirage Swift™ II, the ResMed Swift LT, or the Fisher andPaykel Opus™ 360. A variety of different pillow configurations whichcould be used with these interfaces are described and shown in WO2008/014543.

The prior art still further includes a nasal cannula interface. Thenasal cannula interface includes a plenum portion that rests against theupper lip of the user and a pair of prongs. Each prong extends into thenostril of the user. An example is the Nasal-Aire interface made byInnomed, where gases are provided to the interface and the prongs byconduits or hoses that extend from the users nose across their cheeks,over their ears and around the back of their head.

Interfaces such as these are frequently used for delivering pressurisedgases to a person being treated for obstructive sleep apnea (OSA) orother sleep disorders. These users typically wear the interface in ahome sleeping environment. Comfort and effective sealing even underconditions of patient movement are major considerations.

In this specification where reference has been made to patentspecifications, other external documents, or other sources ofinformation, this is generally for the purpose of providing a contextfor discussing the features of the invention. Unless specifically statedotherwise, reference to such external documents is not to be construedas an admission that such documents, or such sources of information, inany jurisdiction, are prior art, or form part of the common generalknowledge in the art.

The term “comprising” as used in this specification means “consisting atleast in part of”. When interpreting each statement in thisspecification that includes the term “comprising”, features other thanthat or those prefaced by the term may also be present. Related termssuch as “comprise” and “comprises” are to be interpreted in the samemanner.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an interface thatgoes some way towards overcoming the disadvantages of the prior art suchas the devices described above, or which at least provides users with auseful choice.

In a first aspect the invention may broadly be said to consist in anasal pillow section for use as part of an apparatus for providing astream of gases to a user, said pillow section in use located in frontof the upper lip and below the nostrils of a user, said pillow sectioncomprising:

a pillow gasket, having a gases aperture which receives a stream ofgases in use,

nasal pillows, fluidically connected to said pillow gasket and adaptedto substantially seal against the nostrils of a user in use, so thatsubstantially the whole of said stream of gases passes into said nasalpillows from said pillow gasket and is delivered to said user,

the lower inner surface of said pillow gasket shaped so that in usecontact between the upper lip of a user and said pillow gasket isminimised.

Preferably said lower inner surface in said first aspect is shaped as aconcavity.

Preferably said pillow gasket in said first aspect includes an openlower front portion that acts as said gases aperture, and said concavityruns generally between the base or bases of said nasal pillows, and thelower rear part of said open lower front portion.

Preferably the inwards curve of the concavity for said lower innersurface in said first aspect is 3 mm from the lower edge to the upperedge.

Preferably said lower inner surface in said first aspect preferably hasa width of between 30 and 50 mm and most preferably 40 mm.

Preferably the height of said lower inner surface between the outer sideof said pillows and the lower rear part of said open lower front portionwall in said first aspect is preferably between 20 mm and 30 mm and mostpreferably between 25 mm and 27 mm.

Preferably the height of said lower inner surface between the inner sideof said pillows, and the lower rear part of said open lower frontportion wall in said first aspect is preferably between 20 mm and 30 mmand less than the height of said lower inner surface between the outerside of said pillows and the lower rear part of said open lower frontportion wall and most preferably between 23 mm and 25 mm.

Alternatively said lower inner surface in said first aspect is asubstantially straight forward-sloping planar surface.

Preferably said pillow gasket in said first aspect includes an openlower front portion that acts as said gases aperture, and saidsubstantially straight forward-sloping planar surface runs generallybetween the base or bases of said nasal pillows, and the lower rear partof said open lower front portion.

Alternatively said lower inner surface in said first aspect is slightlyconvex.

Preferably said pillow gasket includes an open lower front portion thatacts as said gases aperture, and said slightly convex lower innersurface runs generally between the base or bases of said nasal pillows,and the lower rear part of said open lower front portion, said surfacedeviating 3 min or less from a straight line running between the base orbases of said nasal pillows, and the lower rear part of said open lowerfront portion.

In a second aspect the invention may broadly be said to consist in anasal pillow section for use as part of an apparatus for providing astream of gases to a user, said pillow section in use located in frontof the upper lip and below the nostrils of a user, said pillow sectioncomprising:

a pillow gasket, having a gases aperture which receives a stream ofgases in use,

nasal pillows, fluidically connected to said pillow gasket and adaptedto substantially seal against the nostrils of a user in use, so thatsubstantially the whole of said stream of gases passes into said nasalpillows from said pillow gasket and is delivered to said user,

the lower inner surface of said pillow gasket shaped to include aconcavity.

Preferably said nasal pillow section in said second aspect includes anopen lower front portion that acts as said gases aperture, and saidconcavity runs generally between the base or bases of said nasalpillows, and the lower rear part of said open lower front portion.

Preferably the inwards curve of the concavity for said lower innersurface in said second aspect is 3 mm from the lower edge to the upperedge.

Preferably said lower inner surface in said second aspect preferably hasa width of between 30 and 50 mm and most preferably 40 mm.

Preferably the height of said lower inner surface between the outer sideof said pillows and the lower rear part of said open lower front portionwall in said second aspect is preferably between 20 mm and 30 mm andmost preferably between 25 mm and 27 mm.

Preferably the height of said lower inner surface between the inner sideof said pillows, and the lower rear part of said open lower frontportion wall in said second aspect is preferably between 20 mm and 30 mmand less than the height of said lower inner surface between the outerside of said pillows and the lower rear part of said open lower frontportion wall and most preferably between 23 mm and 25 mm

In a third aspect the invention may broadly be said to consist in anasal pillow section for use as part of an apparatus for providing astream of gases to a user, said pillow section in use located in frontof the upper lip and below the nostrils of a user, comprising:

a pillow gasket, having an open lower front portion which acts as agases aperture and which receives a stream of gases in use,

nasal pillows, fluidically connected to said pillow gasket and adaptedto substantially seal against the nostrils of a user in use, so thatsubstantially the whole of said stream of gases passes into said nasalpillows from said pillow gasket and is delivered to said user,

the lower inner surface of said pillow gasket formed as a substantiallystraight planar surface having an inner upper edge located substantiallyat the base of said pillows and a lower outer edge located substantiallyclose to the lowest point of said open lower front portion.

In a fourth aspect the invention may broadly be said to consist in anasal pillow section for use as part of an apparatus for providing astream of gases to a user, said pillow section in use located in frontof the upper lip and below the nostrils of a user, said pillow sectioncomprising:

a pillow gasket, having a gases aperture which receives a stream ofgases in use,

nasal pillows, fluidically connected to said pillow gasket and adaptedto substantially seal against the nostrils of a user in use, so thatsubstantially the whole of said stream of gases passes into said nasalpillows from said pillow gasket and is delivered to said user,

the lower inner surface of said pillow gasket shaped to be slightlyconvex.

Preferably said pillow gasket in said fourth aspect includes an openlower front portion that acts as said gases aperture, and said slightlyconvex lower inner surface runs generally between the base or bases ofsaid nasal pillows, and the lower rear part of said open lower frontportion, said surface deviating 3 mm or less from a straight linerunning between the base or bases of said nasal pillows, and the lowerrear part of said open lower front portion.

In a fifth aspect the invention may broadly be said to consist in aninterface for use as part of an apparatus for providing a stream ofgases to a user, comprising:

a manifold section, including a gases supply aperture that in usereceives a stream of gases, said manifold section adapted for connectionto a headgear assembly so that in use said interface is held in positionon the face of a user,

a nasal pillow section including a pillow gasket and nasal pillows, saidpillow gasket fluidically connected to said manifold section so thatsaid stream of gases passes through said nasal pillow section in use,said nasal pillows adapted to substantially seal against the nostrils ofa user in use, so that substantially the whole of said stream of gasesis delivered to said user, said pillow section in use located in frontof the upper lip and below the nostrils of a user,

the lower inner surface of said pillow gasket shaped so that in usecontact between the upper lip of a user and said pillow gasket isminimised.

Preferably said lower inner surface in said fifth aspect is shaped as aconcavity.

Preferably said pillow gasket in said fifth aspect includes an openlower front portion that acts as a gases aperture and which isfluidically connected to said manifold section, and said concavity runsgenerally between the base or bases of said nasal pillows, and the lowerrear part of said open lower front portion.

Preferably the inwards curve of the concavity for said lower innersurface in said fifth aspect is 3 mm from the lower edge to the upperedge.

Preferably said lower inner surface in said fifth aspect preferably hasa width of between 30 and 50 mm and most preferably 40 mm.

Preferably the height of said lower inner surface between the outer sideof said pillows and the lower rear part of said open lower front portionwall in said fifth aspect is preferably between 20 mm and 30 mm and mostpreferably between 25 mm and 27 mm.

Preferably the height of said lower inner surface between the inner sideof said pillows, and the lower rear part of said open lower frontportion wall in said fifth aspect is preferably between 20 mm and 30 mmand less than the height of said lower inner surface between the outerside of said pillows and the lower rear part of said open lower frontportion wall and most preferably between 23 mm and 25 mm.

Alternatively said lower inner surface in said fifth aspect is asubstantially straight forward-sloping planar surface.

Preferably said pillow gasket in said fifth aspect includes an openlower front portion that acts as a gases aperture and which isfluidically connected to said manifold section, and said substantiallystraight forward-sloping planar surface runs generally between the baseor bases of said nasal pillows, and the lower rear part of said openlower front portion.

Alternatively said lower inner surface in said fifth aspect is slightlyconvex.

Preferably said pillow gasket in said fifth aspect includes an openlower front portion that acts as a gases aperture and which isfluidically connected to said manifold section, and said slightly convexlower inner surface runs generally between the base or bases of saidnasal pillows, and the lower rear part of said open lower front portion,said convex surface deviating 3 mm or less from a straight line runningbetween the base or bases of said nasal pillows, and the lower rear partof said open lower front portion.

In a sixth aspect the invention may broadly be said to consist in aninterface for use as part of an apparatus for providing a stream ofgases to a user, comprising:

a manifold section, including a gases supply aperture that in usereceives a stream of gases, said manifold section adapted for connectionto a headgear assembly so that in use said interface is held in positionon the face of a user,

a nasal pillow section including a pillow gasket and pillows, saidpillow gasket fluidically connected to said manifold section so thatsaid stream of gases passes through said nasal pillow section in use,said nasal pillows adapted to substantially seal against the nostrils ofa user in use, so that substantially the whole of said stream of gasesis delivered to said user, said pillow section in use located in frontof the upper lip and below the nostrils of a user, the lower innersurface of said pillow gasket directly in front of said upper lip inuse,

the lower inner surface of said pillow gasket shaped to include aconcavity.

Preferably said pillow gasket in said sixth aspect includes an openlower front portion that acts as a gases aperture and which isfluidically connected to said manifold section, and said concavity runsgenerally between the base or bases of said nasal pillows, and the lowerrear part of said open lower front portion.

Preferably the inwards curve of the concavity for said lower innersurface in said fifth aspect is 3 mm from the lower edge to the upperedge.

Preferably said lower inner surface in said sixth aspect preferably hasa width of between 30 and 50 mm and most preferably 40 mm.

Preferably the height of said lower inner surface between the outer sideof said pillows and the lower rear part of said open lower front portionwall in said sixth aspect is preferably between 20 mm and 30 mm and mostpreferably between 25 mm and 27 mm.

Preferably the height of said lower inner surface between the inner sideof said pillows, and the lower rear part of said open lower frontportion wall in said sixth aspect is preferably between 20 mm and 30 mmand less than the height of said lower inner surface between the outerside of said pillows and the lower rear part of said open lower frontportion wall and most preferably between 23 mm and 25 mm.

In a seventh aspect the invention may broadly be said to consist in aninterface for use as part of an apparatus for providing a stream ofgases to a user, comprising:

a manifold section, including a gases supply aperture that in usereceives a stream of gases, said manifold section adapted for connectionto a headgear assembly so that in use said interface is held in positionon the face of a user,

a nasal pillow section including a pillow gasket and pillows, saidpillow gasket fluidically connected to said manifold section so thatsaid stream of gases passes through said nasal pillow section in use,said nasal pillows adapted to substantially seal against the nostrils ofa user in use, so that substantially the whole of said stream of gasesis delivered to said user, said pillow section in use located in frontof the upper lip and below the nostrils of a user, the lower innersurface of said pillow gasket directly in front of said upper lip inuse,

the lower inner surface of said pillow gasket formed as a substantiallystraight planar surface having an inner upper edge located substantiallyat the base of said pillows and a lower outer edge located substantiallyclose to the lowest point of said gases supply aperture.

In an eighth aspect the invention may broadly be said to consist in aninterface for use as part of an apparatus for providing a stream ofgases to a user, comprising:

a manifold section, including a gases supply aperture that in usereceives a stream of gases, said manifold section adapted for connectionto a headgear assembly so that in use said interface is held in positionon the face of a user,

a nasal pillow section including a pillow gasket and pillows, saidpillow gasket fluidically connected to said manifold section so thatsaid stream of gases passes through said nasal pillow section in use,said nasal pillows adapted to substantially seal against the nostrils ofa user in use, so that substantially the whole of said stream of gasesis delivered to said user, said pillow section in use located in frontof the upper lip and below the nostrils of a user, the lower innersurface of said pillow gasket directly in front of said upper lip inuse,

the lower inner surface of said pillow gasket shaped to be slightlyconvex.

Preferably said pillow gasket in said eighth aspect includes an openlower front portion that acts as a gases aperture and which isfluidically connected to said manifold section, and said slightly convexlower inner surface runs generally between the base or bases of saidnasal pillows, and the lower rear part of said open lower front portion,said surface deviating 3 mm or less from a straight line running betweenthe base or bases of said nasal pillows, and the lower rear part of saidopen lower front portion.

In a ninth aspect the invention may broadly be said to consist in asystem for providing a heated, humidified stream of gases to a user,comprising:

a blower unit having a blower outlet and adapted to supply a stream ofgases at a pressure above atmospheric from said blower outlet,

a humidifier unit having a humidifier inlet and a humidifier outlet,said humidifier inlet fluidically connected to said blower outlet, saidhumidifier unit in use receiving said stream of gases and heating andhumidifying said stream of gases, before passing said gases out of saidhumidifier outlet,

an interface including a gases supply aperture,

a supply conduit, one end of said supply conduit fluidically connectedto said humidifier outlet to receive said stream of heated humidifiedgases, the other end of said supply conduit fluidically connected tosaid gases supply aperture to provide said stream of heated humidifiedgases to said interface,

a headgear assembly, said interface and said headgear assembly mutuallyadapted to connect together and hold said interface in position on thehead of a user in use,

said interface as described in any one of the statements relating to thefifth to eighth aspects above.

To those skilled in the art to which the invention relates, many changesin construction and widely differing embodiments and applications of theinvention will suggest themselves without departing from the scope ofthe invention as defined in the appended claims. The disclosures and thedescriptions herein are purely illustrative and are not intended to bein any sense limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

One preferred form of the present invention will now be described withreference to the accompanying drawings in which:

FIG. 1 shows a schematic view of a system for supplying a stream ofheated humidified gases to a user via an interface assembly, the systemincluding a gases supply unit or blower, a humidifier chamber, and asupply conduit connecting the humidifier chamber and the interfaceassembly.

FIG. 2a shows a perspective view from the front and to one side of afirst preferred embodiment of the interface assembly of the presentinvention, showing an interface core portion or core section adapted toconnect to the supply conduit so the interface can receive gases fromthe gases supply unit in use, a nasal pillow section included as part ofthe interface core section, and a headgear assembly connected to thecore section which is adapted to hold the interface in position on thehead of a user.

FIG. 2b shows the interface of FIG. 2a in use, being worn by a user,viewed from the same angle as FIG. 2 a.

FIG. 2c shows an exploded view of the interface of FIG. 2a or 2 c.

FIG. 3a shows a second preferred embodiment of the interface assembly ofthe present invention, the second preferred embodiment containingsimilar elements to those of the first preferred form of FIG. 2 butconfigured slightly differently.

FIG. 3b shows the functionality of the connection between the supplyconduit and the interface core section of the second preferredembodiment of FIG. 3 a.

FIG. 3c shows a close-up view of the interface core portion or coresection of FIG. 3 a.

FIG. 4a shows a third preferred embodiment of the interface assembly ofthe present invention in use being worn by a user, the interfaceassembly of this third preferred form having similar elements to thoseof the preferred embodiments of FIGS. 2 and 3, but configured slightlydifferently.

FIG. 4b shows an exploded perspective view from the front and to oneside of the interface assembly of FIG. 4 a.

FIG. 5a shows a first preferred form of nasal pillow section for use aspart of either of the first or second preferred embodiments of interfaceassembly as shown in FIG. 2 or 3, the nasal pillow section having anasal pillow gasket section and nasal pillows connected to the nasalpillow gasket section, the nasal pillow section shown being viewed fromthe rear looking forwards.

FIG. 5b shows the nasal pillow section of FIG. 5a , viewed from a user'sright hand side if the nasal pillow section was in use as part of aninterface being worn by a user.

FIGS. 5c and 5d show the nasal pillow section of FIGS. 5a and 5b , withdimension lines added to show the critical dimensions.

FIG. 6a shows a second preferred form of nasal pillow section for use aspart of either of the first or second preferred embodiments of interfaceassembly as shown in FIG. 2 or 3, the nasal pillow section having anasal pillow gasket section and nasal pillows connected to the nasalpillow gasket section, the nasal pillow section shown being viewed fromthe rear looking forwards.

FIG. 6b shows the nasal pillow section of FIG. 6a , viewed from a user'sright hand side if the nasal pillow section were in use.

FIG. 7a shows a third preferred form of nasal pillow section for use aspart of either of the first or second preferred embodiments of interfaceassembly as shown in FIG. 2 or 3, the nasal pillow section having anasal pillow gasket section and nasal pillows connected to the nasalpillow gasket section, the nasal pillow section shown being viewed fromthe rear looking forwards.

FIG. 7b shows the nasal pillow section of FIG. 7a , viewed from a user'sright hand side if the nasal pillow section were in use on the face ofthe user.

FIG. 8a shows a side view of a fourth preferred form of nasal pillowsection for use as part of the third preferred embodiment of interfaceassembly as shown in FIG. 4.

FIG. 8b shows a perspective view from the front and to one side of thefourth preferred form of nasal pillow section of FIG. 8a , partiallycut-away or transparent so that the outline of the wall and internalstructure of the nasal pillow section can be seen.

FIG. 8c shows a side view of a modification of the fourth preferred formof nasal pillow section shown in FIG. 8 a.

FIG. 8d shows a side view of another modification of the fourthpreferred form of nasal pillow section shown in FIG. 8 a.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides an interface for use as part of anapparatus for providing a stream of gases to a patient. The preferredand alternative embodiments are for use as part of an apparatus forproviding a stream of heated, humidified gases at a pressure aboveatmospheric pressure to a user for the purposes of CPAP therapy orsimilar. However, it should be noted that the interface is not limitedfor use as part of an apparatus for providing CPAP therapy—the interfacecould also be used for Bi-PAP or variable pressure therapy, as part ofan apparatus used for an anti-snoring treatment regime, for thetreatment of COPD, or as part of any therapy regime where a stream ofgases at a pressure greater than atmospheric is delivered to thebreathing passages of a patient or user via an interface assembly.

The preferred embodiment will now be described in detail with referenceto the Figures. However, it should be noted that many variations arepossible which have not been specifically described, without departingfrom the intended scope of the present invention.

Gases Supply System

FIG. 1 shows a schematic view of a typical system 1 for providing astream of heated humidified gases at a pressure above atmospheric to auser 2. The system 1 includes a gases supply unit or blower unit 3 whichin use receives gases from atmosphere and passes these through a fanunit 17 or similar inside the blower unit so that when the gases leavethe blower unit 3, they are at a pressure above atmospheric, and areflowing at a certain flow rate. A humidifier unit 4 is locateddownstream from the blower unit 3, and in use receives the flow ofpressurised gases from the blower unit 3. The humidifier unit 4 includesa water chamber 5 which in use contains a volume of water 7. The volumeof water 7 in the chamber 5 is in use heated—in the embodiment shown inFIG. 1, the water 7 is heated by a heater plate 6 located underneath thechamber 5. The gases from the blower unit 3 pass into the chamber 5 viaan entry port 8, the gases passing through the chamber 5 and across thesurface of the water 7, becoming heated and humidified as they do so.The gases then pass out of the humidifier chamber 5 via a humidifieroutlet port 9. It should be noted that there are many different ways inwhich the gases could be heated and humidified aside from the specificway described above, and any of these different ways are suitable foruse as part of the system that uses the pillows of the presentinvention.

It should also be noted that a modular system has been describedabove—that is, a system where the humidifier unit 4 is a separate unitto the blower unit 3. An integrated system could also be used—that is, asystem where the blower unit and the humidifier unit are two integralparts of a single unit, or where the blower unit and the humidifier unitare rigidly attached or connected together in use.

In use, one end of a main supply conduit 19 is connected to thehumidifier outlet 9. The heated and humidified gases stream exits thehumidifier unit 4 via the humidifier outlet 9 and enters the main supplyconduit 19, passing along the supply conduit 19 to an interface assembly10 which is connected to the user end of the supply conduit 19. Thesupply conduit 19 can either be directly connected to the interfaceassembly 10, as shown in FIG. 1, or an intervening interface conduit 190can be used to connect between the main supply conduit 19 and theinterface assembly 10, as shown in the embodiments of FIGS. 2, 3 and 4.Where the supply conduit 19 is referred to below, this should be takento mean either the supply conduit 19 by itself, or alternatively asreferring to the supply conduit in combination with the interfaceconduit 190.

Supply Conduit and Interface Conduit

In the preferred embodiment, the supply conduit 19 is a flexible tubeformed from a plastic type material, many different variations of whichare known in the art. One end of the supply conduit 19 is connected tothe humidifier outlet port 9, with the other end connected eitherdirectly to the interface assembly 10, or connected to the distal end190 a of the interface conduit 190, the interface conduit 190 connectedto the interface core section 11. The most preferred form of interfaceconduit 190 is approximately 30 cm or 1 foot in length, with an externaldiameter of between 1-2 cm and a thin ribbed wall, the ribs beingapproximately 2-3 mm thick and the wall between the ribs beingsignificantly less that 1 mm thick. However, it should be noted thatvariations from these dimensions are possible without departing from thescope of the invention, and for example a non-ribbed conduit could beused if required. It should further be noted that ‘flexible tube’ as itis used in this specification should be taken to mean that the tube orconduit is flexible enough so that it is capable of being bent ordeformed repeatedly (for example, by bringing the two ends of theconduit together, or by tying a loose knot in the conduit if it is longenough—e.g. approximately 30 cm or more in length), with the tube orconduit returning to its original undeformed shape with little to noplastic deformation occurring, every single time the tube or conduit isbent or deformed in this manner.

In the most preferred form, neither of the supply conduit 19 or theinterface conduit 190 will rigidly support their own weight when held atone end so that the main body of the conduit extends outwards generallyhorizontally from the held end. Over a 20-30 cm length of supply conduit(which has a diameter of 1-2 cm and a wall thickness at the ribs of 1-3mm and a wall thickness between the ribs of less than 1 mm), theunsupported end of the interface conduit will bend to face substantiallydirectly downwards. For example, the interface conduit of the Swift LT™is formed in such a manner that over a 20-30 cm length, the unsupportedend will bend downwards so that it points substantially verticallydownwards. The interface conduit used in the Opus is somewhat stiffer,but will still bend through an angle of very approximately 45 degrees.Both of these conduits are flexible for the purposes of thisspecification, and should not be thought of as ‘rigid’ or ‘semi-rigid’(see Lexicon section for more details). The main supply conduit 19 is ofsimilar flexibility to both of these items, but is generally slightlyless flexible.

The conduits 19, 190 connect to each other, or to the interface assembly10, or both, by a friction push fit, a bayonet connection or similar, orby any other suitable connection as might be known in the art.

Interface Assembly

Specific preferred forms of an interface assembly are shown in FIGS. 2,3, and 4 as interface assembly 200, interface assembly 300 or interfaceassembly 400. The interface assemblies 200, 300, 400 have a number ofcommon elements and differences as will be described below. In thedescription below, the element numbering conforms to the followingconvention: For the embodiment of FIG. 2, the elements unique to thatembodiment will be numbered e.g. 201, 210, etc. The equivalent uniqueelements on the embodiments shown in FIGS. 3 and 4 will be numbered e.g.301, 310 and 401, 410 respectively. If the element is being referred toin a general sense, it will be referred to as e.g. 1, 10 etc to showthat the description is applicable to all the embodiments shown in FIGS.2, 3, 4, and could also be applied as a general description to other,general, embodiments not specifically shown.

The interface assembly (e.g. assemblies 200, 300, 400) are assembledfrom two main parts: an interface core portion or interface core section11, and a headgear assembly 12.

The interface core section 11 and the supply conduit 19 (eitherincluding or excluding the interface conduit 190) are mutually adaptedso that one end (the patient end or proximal end) of the supply conduit19 is fluidically or gaseously connected to the interface core section11 in use, the interface core section 11 adapted so that the supply ofheated, humidified gases is provided to the interior of the interfacecore portion 11 from the supply conduit 19 via this connection. Thepreferred forms of this connection will be described in detail below.

Headgear Assembly

The headgear assembly 12 is formed from two main items: a set of arms 13that extend in use one from each side of the interface core portion 11,and a set of headgear straps 14. In the preferred embodiments, the arms13 are formed from either a flexible or a semi-rigid plastic, backedwith neoprene, foam, or similar to form a cushion portion, the cushionportion resting against the face of a user in use.

The arms 13 can be connected to the interface core portion 11 in anumber of ways. For example, arms 213 could be integrally formed orintegrally connected with the interface core portion 211, as shown inthe embodiment of FIG. 2—the arms 213 are formed as part of theinterface core portion 211. Alternatively, the arms, such as arms 313,could be removably or releasably connected to the interface core portion311 as shown in the embodiment of FIG. 3a . In the specific embodimentof FIG. 3a , the releasable connection is made in such a manner as toallow the arms 313 to be rotatably adjusted with respect to theinterface core portion 311. The embodiment of FIG. 3a with theadjustable arms shows an interface assembly 300 that has an interfacecore portion 311 and arms 313. The interface ends of the arms 313 arerotatably connected to the interface core portion 311 by way of a‘rotating barrel’ connection as is used on the ResMed Swift™ LT, whichallows the arms 313 to rotate relative to the interface core portion311, and still remain connected. The mutual connection is formed so thatwhen the connection is made, the arm 313 will remain in the position towhich a user has rotated it—the arm 313 will not freely rotate unlessmanipulated by an external force.

For all of the preferred forms, the headgear straps 14 extend around therear, or over the top of a user's head (or both) in use, to support theinterface assembly 10 in position in use. In the embodiment of FIG. 2,the ends of the arms 213 in use co-locate with the ends of the headgearstraps 214, with the ends of the arms 213 and the ends of the headgearstraps 214 mutually adapted to connect together in use to hold theinterface assembly 200 in position. In this form, the ends of the mainstrap 214 include two patches of Velcro™ on the outer surface at eachend—one ‘hook’ patch and one ‘loop’ patch. When each of the ends isdoubled back on itself to form a loop, the Velcro™ patches engage tohold this loop together. In use, the ends 224, 225 are passed one eachthrough slots 280 on the ends of the arms 213 and then doubled back onthemselves to engage the headgear assembly 212 with the core section211. This arrangement could be used on other embodiments if required.

In alternative embodiments, such as those shown in FIGS. 3 and 4, theheadgear straps 314, 414 could be formed as an extension of the cushionportion, with the headgear straps 314, 414 formed from neoprene orsimilar. For example, in the embodiment shown in FIG. 3, the headgearstraps 314 are a single-piece item with the arms 313.

It is preferred that all the different embodiments of headgear straps 13include a secondary upper strap 20 which passes across the top of auser's head, as well as the main strap 14 which passes behind the user'shead. The secondary upper strap 20 is arranged so that it passes acrossthe top of a users head, with each end of the secondary strap 20connecting to the main strap 14 just behind the ears of a user. Each ofthese straps 14, 20 includes an adjustment mechanism such as buckles 15a, 15 b or similar. These could be Velcro™ adjusters or buckles aspreferred. The headgear secondary upper strap 20 could also beindependently formed and connected to the main strap 14. The adjustmentscould be at any location on the strap that is convenient—sides, front orrear. The straps 14, 20 could be of different widths or thicknesses asrequired for user comfort. For example, in the most preferred form, themain strap 14 is wider than the secondary strap 20.

Suitable strap materials may include a woven elastic strip or a narrowstrip of foam and fabric, such as Breathoprene™. Alternatively, theheadgear could be formed from silicone, or coated with silicone. Theheadgear arms could be padded or cushioned on their inside surfaces ifthey are formed from silicone, in order to increase user comfort.Padding could also be added to the preferred form of arms—those madefrom Breathoprene™ or similar.

Interface Core Section—General

The interface core section 11 of the preferred forms is formed so as toact as a manifold in use, receiving gases from the supply conduit 19.The connection between the interface core section 11 and the patient oruser end of the supply conduit 19 can be made by way of a push-fitconnection or similar. In one preferred form (not specifically shown),the interface core section 11 is formed as a one-piece item, and anaperture or connector portion which is adapted to receive the patientend of the supply conduit 19 is formed directly in this one-piece item.In this form, the end of the supply conduit 19 is connected directly tothe one-piece interface core section 11—e.g. by pushing it into theaperture located on the interface core section 11, or by connecting itto the connector portion. However, in other preferred forms, thisaperture is located on a separate sub-item or sub-assembly that isincluded as part of the interface core portion 11 when the interfacecore section 11 is assembled, but is initially formed as a separateitem.

Interface Core Section—First Preferred Form

An example of an interface core section 211 that has a manifold sectionand a connector that is initially formed as a separate item is shown inFIG. 2. The interface core section 211 includes a manifold section 211-1and an elbow connector 211-2. One end of the elbow connector 211-2 isformed as a ball joint 290, and this locates into a socket 291 on thefront of the manifold section 211-1 in use, the socket 291 adapted toact as a gases supply aperture. This allows a degree ofthree-dimensional relative movement, or movement in more than one plane,between the manifold section 211-1 and the elbow connector 211-2. Thatis, as well as being able to rotate through 360 degrees in a planerunning across the front of a user's face, the elbow connector 211-2also has a limited degree of up/down rotation and side/side rotationrelative to the manifold section 211-1.

Interface Core Section—Second Preferred Form

An example of a second preferred form of interface core section 311 thatincludes an elbow connector is shown in FIG. 3a . A manifold portion ormanifold section 311-1 is shown, the manifold section 311-1 including anaperture located at the front of the manifold section 311-1. An elbowconnector 311-2 is connected to the manifold section 311-1 via theaperture, with one end of the elbow connector 311-2 locating into orconnected to the aperture, and the other connected to the supply conduit190. The manifold section 311-1 and the elbow connector 311-2 aremutually adapted to provide a 360 degree swivel—the elbow connector311-2 and the manifold section 311-1 can swivel or rotate through 360degrees relative to one another in use, in a plane across the front of auser's face, as shown in FIG. 3b . The manifold section 311-1 and theelbow connector 311-2 are assembled together to form part of theinterface core section portion 311 of the embodiment of FIG. 3.

Interface Core Section—Third Preferred Form

Yet another example of an interface core section that includes an elbowconnector is shown in FIG. 4. The manifold section 411-1 includes anaperture at one side of the manifold section 411-1. This aperturereceives one end of an elbow connector 411-2 in use, the elbow connector411-2 adapted to rotate freely relative to the manifold section 411-1,the plane of rotation of the elbow connector aligned back-front of auser 2 in use, rather than side-side as in the embodiment of FIG. 3 b.

Interface Core Section—Pillow Section

The interface core section 11 also includes a pillow section 50, thepillow section including pillows 50-1 which are adapted to substantiallyseal against the nares of a user in use. The pillow section 50 isfluidically connected to the manifold section 11-1 so that in use theheated, humidified gases stream enters the pillow section 50 from themanifold section 11 and passes through the pillows 50-1 into the nasalcavity of a user. ‘Substantially seals’ as it is used in thisspecification should be taken to mean that perfectly sealing against thenares with no leaks is the most desirable outcome. However, a smalldegree of leakage in use is almost certainly inevitable, and a personskilled in the art will understand that the phrase ‘substantiallysealing’ is intended to indicate that a very small amount of leakage maysometimes, but not always, occur. As the pillows 50-1 are substantiallysealed against the nares of a user, all or substantially all of thestream of gases which passes through the manifold section 11 and thenasal pillow section 50 will be delivered to a user.

As shown in the preferred embodiments of FIGS. 2, 3 and 4, the pillowsection 50 is composed of two main sub-parts that form a continuous orintegrated whole in use: pillows 50-1, which locate into the nares ofthe user or patient 2 in use, and a pillow manifold section or pillowgasket 50-2, which is connected to the interface core section 11 in use,so that gases passing through the core section 11 in use will then passinto the pillow gasket 50-2 and from there into the pillows 50-1.

In order to aid in sealing the nasal pillows 50-1 against the nares of awide variety of users, each of whom will have differently shaped andsized nostrils, the pillows 50-1 are in the preferred form formed from asoft and supple material with a high degree of flexibility, such assilicone rubber or similar. Preferred forms of the nasal pillows 50 aredescribed in detail below.

The nasal pillow section 50 can either be formed separately from therest of the core portion 11, or integrally formed with the core portion11. In the preferred embodiments as shown in FIGS. 2, 3 and 4, the nasalpillow section 50 is a separate item to the core portion 11.

The nasal pillow section 50 is formed from two main parts in the threepreferred fowls described herein: a base portion or nasal pillow gasketportion 50-2, and nasal pillows 50-1. The attachment or connection ofthe nasal pillow section 50 to the remainder of the core portion 11 isachieved by attaching the gasket portion 50-2 to the manifold portion11-1, with the pillows 50-1 preferably (although not always) integrallyformed with the gasket portion 50-2. The embodiments of FIGS. 2, 3 and 4show this form of connection.

In the preferred embodiments, at least the pillows 50-1 are formed froma supple and flexible material, such as silicone rubber.

Pillow Gasket—First Preferred Form

The first preferred form of pillow gasket portion 250-2 shown in FIG. 2shall now be described with particular reference to FIG. 2c and FIGS. 5,6 and 7.

The preferred form of pillow gasket portion 250-2 includes an open lowerface or open lower front portion 237 which corresponds in use to theopen rear face (not shown) of the manifold section 211-1, so that in useit acts as a gases aperture. It should be noted that the open rear faceand the open lower portion 237 could be apertures—these do not have tocover the entire ‘face’. In use, the perimeter of the open lower portion237 of the pillow gasket portion 250-2 is connected to the open rearface of the manifold section 211-1. The wall 237 a which surrounds theopen lower portion 237 slots or locates into the open rear face of themanifold section 211-1, and substantially seals against it. It can beseen that all of the gases passing through the manifold section 211-1will pass into the pillow gasket portion 250-2 and from there into thenasal pillows 250-1. It should be noted that the pillow gasket portion250-2 can be attached and removed repeatedly from the manifold portion211-1 as required by a user. Optionally, if required, a key 238 can beformed into the wall section 237, the key 238 slotting into acorresponding slot in the manifold section 211-1 to ensure the pillowsare correctly oriented in use.

In the first preferred form of pillow gasket portion 250-2, the pillowgasket 250-2 is shaped so that the two side portions are slightly angledtowards one another. That is, the top surface which covers the open rearface of the manifold 8 appears to have a V-shape when viewed from thefront, with the pillows 250-1 one on each of the two sub-surfaces orinner faces of the ‘V’. The angle of the ‘V’ is not acute—each edge orplane of the ‘V’ of the pillow gasket portion 250-2 is raised by a fewdegrees only (e.g. 5-10 degrees). The pillows 250-1 are mounted one oneach of the two planes, and are in this manner angled inwards towardsone another slightly in the most preferred form (although there are ofcourse many other ways in which this could be achieved without creatinga ‘V’-shape).

In the preferred form, as described above, the nasal pillows 250-1 andthe gasket portion 250-2 are formed as a one-piece item. However, thepillows 250-1 could be removably connected to the gasket portion 250-2,either individually or as a pair. For example, the gasket portion 250-2could include a pair of stub bases to which the pillows are press-fittedin use, the stub base and the base of the stem 250-3 being mutuallyadapted to connect together by way of a press-fit, a keyed connection,or similar. This would potentially allow pillows which are of differentshapes or sizes to be fitted to the pillow gasket portion 250-2. Thiswould be advantageous if a user required pillows moulded specifically tothe shape of their nares, or pillows of different sizes. This would alsoallow a range of standard pillows to be manufactured, the range havingdifferent sizes or different shapes, or both. This would provide a rangeof off-the-shelf adjustment.

In the very most preferred forms, the pillow gasket portion 250-2 isformed so that in normal use, the pillow gasket portion 250-2 is heldoff or apart from the upper lip of a user 2, the intention being thatthere is no contact or minimal contact between the gasket portion andthe lip of a user in use. When the phrase ‘no contact’ is used in thisspecification, it should be taken to mean that there is no intentionalcontact, and any contact that does occur is outside the intended normaloperating condition of the interface. Surprisingly, and in contrast withwhat has previously been known in this area of the art, it has beenfound that minimising contact with the upper lip of a user is in certaincircumstances beneficial. Some prior art devices have actively used theupper lip as a support for the pillow gasket portion, even in some casesgoing as far as to have a lower rear portion of the gasket which can beat least semi-inflated by the gases passing through the pillow gasket.It is intended in these designs that the inflated/inflatable lower rearportion acts as a lip cushion and aids in providing support.

Surprisingly however, it has been found that having a pillow gasketwhich minimises contact with the upper lip of a patient can also bebeneficial for some users, and can act to increase the user's comfortlevels and compliance with their therapy regime. Surprisingly, it hasalso been found that movement of a user's upper lip can in some caseshave more of detrimental effect on the sealing of pillows against thenares of a user 2 than is known in the art at the present time, or wasanticipated. Because this detrimental effect was not anticipated, it wasnot compensated for when designing the interfaces which are currentlyknown in the art. It has been found that in some cases when using theprior art interfaces that movement of the user's lip causes an excessiveamount of movement of the interface core portion and pillows—more thanwas originally anticipated for interface designs which include lipcushions. Therefore, when using the prior art designs, there is anincreased likelihood that the seal between the nares of a user 2 and oneor both of the pillows 50 will fail, at least momentarily. The pillowsof the present invention offer a useful, new, and surprising alternativeto the prior art, with contact between the pillows and the lip minimisedas far as possible.

There are several different ways this minimised or no contact can beachieved. The preferred forms will now be described with particularreference to FIGS. 5, 6 and 7.

In the first most preferred form as shown in FIG. 5, the lower innersurface 500 of the pillow gasket portion 250-2 appears inwardly-slopingor concave when viewed directly from one side—the surface is formed toinclude a concavity. The concavity in this preferred form runs generallybetween an area at or close to the lower end or base of the stem 253 ofthe pillows 250-1, and the rear of the wall 237 a (however, it should benoted that the concavity could run between any convenient points—it doesnot have to be restricted to these points). This concavity ensures thatcontact between the users face and the pillow section 250 occurs only atthe nasal pillows 250-1 during the majority of usage, and there is nocontact in use with the upper lip of a user 2, or that what contact doesoccur is minimised.

The critical dimensions of the very most preferred form are shown inFIGS. 5c and 5d . Dimension line 1000 on FIG. 5c shows the widthdimension across the lower inner face 500 of the pillow section 250 forthe very most preferred form, this being 40 min. Dimension line 1001 onFIG. 5c shows the preferred height of the face 500 between the base ofthe pillows 250 on the outer side, and the wall 237 for the very mostpreferred form, this being 26.5 mm. Dimension line 1003 on FIG. 5c showsthe preferred height of the face 500 between the base of the pillows 250on the inner side, and the wall 237 for the very most preferred form,this being 24.5 mm. Dimension line 1002 on FIG. 5d shows the inner curveof the concavity for the face, showing that the upper edge of the face500 is 3 mm further forward than the lower edge of the face 500 in themost preferred form. It should of course be noted that these dimensionsare the dimensions of the most preferred form, and a range of e.g. 5 mmand possibly up to 10 mm or more either side of these dimensions ispossible.

The lower inner surface 500 could alternatively be a substantiallystraight planar surface running between the lower end or base of thestein 253 and the rear of the wall 237 a. That is, this forward end oredge of the plane in the embodiment of FIG. 2 will be just behind thelowest part of the gases supply aperture 291. However, concave ispreferred for this first most preferred form, as this provides the mostroom for movement of the upper lip of a user 2 without contactoccurring.

It can be seen that the planar surface will be at an angle to thevertical—it will be forward-sloping, with the lower edge forward of therear edge, the angle of slope dictated to a great extent by thelocations of the gases supply aperture of the manifold section, and thelower end or base of the stems. It should be noted that the plane doesnot have to begin and end at these positions, but it is preferred thatthe edges are substantially at these positions.

As shown in FIG. 5a , the first preferred form of pillows 250 alsoincludes a bridging platform 254 which runs between the stems 253 of thepillows 250-1. The bridging platform 254 helps to localise as much ofthe movement of the pillows to the region closest to the user's nares.This localisation of the movement assists in helping to avoid any leaksthat may develop from the patient moving their lip while wearing theinterface. The bridging platform 254 is an area between the pillows thatis stiffer than the remaining material around the base of the stems 253,the stems 253 themselves, and the caps 255 of the pillows. In the mostpreferred form, the bridging platform 254 is created by thickening anarea—that is, using a thicker material in that area or section toincrease the stiffness in that area. Surprisingly, it has been foundthat making the lower rear surface 500 concave as described above andalso combining this with the bridging platform such as platform 254provides unexpected benefits. The concave surface can be shaped in sucha manner as to minimise contact between the user's lip and the surface500, and also so that the platform 254 is supported and movement of thepillows 250-1 is localised.

In the embodiment shown in FIG. 5, the stems 253 are flared towardstheir top end, where the stems 253 meet and merge with the bottom of thecaps 255. It should be noted that if required, the stems 253 couldalternatively be straight-sided, or at least not flared towards the topend.

The second most preferred form will now be described with reference toFIG. 6. The second most preferred form is very similar to the first mostpreferred form described above with reference to FIG. 5. However, as canbe seen from FIG. 6b , the lower rear surface 600 or support structure600 is very slightly outwardly sloped or slightly convex. In thiscontext, slightly outwardly sloped or slightly outwardly bowed isdefined as follows: the surface 600 never deviates more than 3 mmoutwards from a straight line drawn between the two ends (i.e. if astraight line 601 were drawn between point A and point B on FIG. 6b ,this line can be thought of as defining a plane passing across the rearof the actual pillow gasket portion 250-2. For the actual pillow gasketportion 250-2, stating that the surface 600 is slightly outwardly slopedmeans that there is never a deviation of more than 3 mm from the planedefined by line 601 for the actual pillow gasket portion 250-2 when itis manufactured.

In a similar fashion as for the first most preferred form describedabove with reference to FIG. 5, the second preferred form also includesa bridging platform—bridging platform 264—which runs between the stems263 of the pillows 250-1. The combination of the bridging platform 264and surface 600 is similar to that described above: in combination theseelements can be formed so that not only is contact between the lip of auser 2 and the interface minimised, but also the platform 264 issupported and movement of the pillows 250-1 is localised.

The third preferred form of pillow gasket will now be described withreference to FIG. 7. FIGS. 7a and 7b show a design that is very similarto that of FIG. 5. This form or embodiment is slightly different to thatshown in FIGS. 5a and 5b as it has a bridging platform 274 that sits asfar away from the lip as possible without compromising the localisedmovement of the pillows provided by the bridged platform design. This isachieved by including an indented profile 701 as part of the design.This has the surprising advantage that the inwardly sloping support faceor concave face 700 in combination with the indented profile 701 of thebridging platform 274 will minimise contact between the elements of theinterface and the face of a user, and still provide sufficient support.

It should be understood that there are several other design requirementsfor a patient interface, and in particular the interface core sectionand pillows, aside from increasing user comfort and compliance byminimising contact with the users upper lip (where this minimisedcontact is considered to be appropriate or beneficial). For example, aswell as user comfort, there is the requirement that a good seal isformed between the pillows and the nares, that the pillows and gasketform an internal gases passageway that is of a size and shape to allowthe passage of heated humidified gases without overly impeding the gasesflow and without causing gases flow or pressure to be outside adesirable range, etc. A person skilled in the art, having access to thedescription relating to the preferred embodiments as outlined above andbelow, would be able to ascertain e.g. the exact dimension or shapewhich they require from within a suitable range, which would have thedesired overall effect.

Pillow Gasket—Second Preferred Form

The second preferred form of pillow gasket is shown in FIG. 3, and isdescribed below with particular reference to FIG. 3c . This secondpreferred form shares many of the features of the first preferred form,including the three preferred forms of pillow gasket portion describedabove. That is, the pillow gasket portion 350-2 of this second preferredform can include features such as for example the surfaces 500, 600 and700 and the indented profile 701 as described above, and these aredimensioned in a similar fashion to the preferred form 250 describedabove. As described above, the manifold section 311-1 includes anaperture located at the front of the manifold section 311-1, where anelbow connector 311-2 is connected to the manifold section 311-1. Theforward end or edge of the forward-sloping plane in the embodiment ofFIG. 3 will be just behind the lowest part of this gases supplyaperture.

The main difference between the pillow gasket portion 250-1 and thepillow gasket portion 350-2 is that the second preferred form of pillowgasket 350-1 is held in position on the manifold section 311-1 by a pairof protrusions 338 on the gasket portion 350-2 which slot intocorresponding apertures on the manifold section 311-1. In the form shownin FIG. 3c , the protrusions 338 and the apertures are aligned centrallyon the manifold section 311-1 and the gasket portion 350-2. However,this potentially allows the gasket portion 350-2 to be fittedupside-down on the manifold section 311-1, so if required these can beoffset to the sides, so that the gasket portion 350-2 can only beconnected in one (correct) orientation.

Pillow Gasket—Third Preferred Form

A third preferred form of pillow gasket is shown in FIG. 4, and isdescribed below with particular reference to FIG. 4b and FIGS. 8a and 8b.

The manifold section 411-1 and the main body of the gasket section 450-2of the pillow section 450 of this third preferred form when assembledfor use have the overall general form of a cylinder, which in use isaligned across the top lip of a user. The manifold section 411-1includes an aperture at one side of the manifold section 411-1, formedin the end section 411-1 b, the aperture adapted to receive one end ofthe elbow connector 411-2 in use. The elbow connector 411-2 and themanifold section 411-1 are adapted to rotate freely relative to eachother in use, the plane of rotation of the elbow connector alignedback-front of a user 2 in use, rather than side-side as in theembodiment of FIG. 3.

In this third preferred form, the pillow section 450 is removablyattached to manifold section 411-1. When the pillow section 450 and themanifold section 411-1 are connected, the two nasal pillows 450-1 extendoutwards and upwards from the cylindrical main portion, towards thenares of a user 2 in use.

The manifold section 411-1 is formed from a semi-rigid plastic, with acentral cross-brace body section 411-1 a, and two end sections 411-1 band 411-1 c. A cap 470 closes off one end—end 411-1 c—in use (theopposite end from the elbow connector 411-2).

The gasket section 450-2 of the pillow section 450 has the generaloverall form of a cylinder, the gasket section 450-2 and the manifoldsection 411-1 mutually sized so that the gasket section 450-2 slotsbetween the end sections 411-1 b and 411-1 c. The gasket section 450-2includes a slit 451 which runs along the length of the cylindrical body,at the bottom front of the cylindrical body, opposite the pillows 450-1.In use, the slit 451 in the gasket section 450-2 is held closed byengagement of the edges of the slit with the cross-brace body section411-1 a.

The ends of the headgear straps 413/414 in this third preferred forminclude connectors 452 which engage with the ends of the manifoldsection 411-1 to hold the manifold section and pillow section 450 inplace on the face of a user in use.

In a similar manner to that described above for the first and secondpreferred forms or preferred embodiments, the lower rear part of thegasket section 450-2 can if required) be rounded inwards in a concavefashion, so that there is no contact between the upper lip of a user 2and the rear of the gasket portion 450-2 of the pillow section 450 ofthe third preferred form. One way in which this concavity can beachieved is shown in FIG. 8, with the lower inner surface 800 concave orcurved inwards. FIG. 8a shows one style of concavity, the surface 800re-curving outwards at the lower part of the concavity, towards thebottom or lower portion of the gasket portion 450-2. FIG. 8c shows asecond style of concavity, with the lower part or portion of the surface800 ending closer to the lower inner edge or side of the slit 451 thanthe first style shown in FIG. 8 a.

In a similar manner to the first and second preferred forms, theconcavity is intended to minimise contact in use with the upper lip of auser 2. The lower inner surface 800 could alternatively be a straightplanar surface running between the lower end or base of the stems 453and the lower inner edge or side of the slit 451, or another appropriatepoint or plane running across the rear of the gasket portion 450-2—forexample, the outer, lower edge of the planar surface could besubstantially close to the lowermost point of the gases supply apertureformed in the end section 411-1 b (which is also substantially close towhere the lower inner edge or side of the slit 451 is located). One‘straight surface’ example is shown in FIG. 8d . However, concave ispreferred (as in FIGS. 8a and 8c ), as this provides the most room formovement of the upper lip of a user 2 without contact occurring.

A bridging platform (not shown) can also be used in a similar fashion tothe bridging platforms 254, 264, 274 as described above in relation tothe first and second gaskets. The bridging platform can include anindented profile if required, similar to that already described.

The stems 453 for this form are shown as flared towards their top end,where the stems 453 meet and merge with the bottom of the caps 455. Itshould be noted that if required, the stems 253 could alternatively bestraight-sided, or at least not flared towards the top end.

Pillows

As described above, there are three particularly preferred forms ofinterface assembly, which have several common elements and severalelements which are unique to that particular preferred form. Manydifferent forms of pillow design can be used with the preferredembodiments described above. For example, the pillows shown in thepreferred embodiments of FIGS. 1 to 8 all have a single-walled cap 55and a smooth-walled stem 53, the stem flaring at the upper end, towardsthe cap 55.

It should be noted that different designs of pillow can be used with thepreferred forms of interface assembly as described above. For example,the stems or stalks 53 could be ribbed, as described in co-pending U.S.application 61/060,855, the contents of which are incorporated byreference.

Also, if required, pillows having a double-cap structure (an inner capand an outer cap) could be used.

It should also be noted that a ‘single pillow’ structure could be used,with one pillow or item delivering gas to the nostrils of a user—forexample, a pillow structure with a single stern that bifurcates into twocaps just below the nostrils, or a single cap shaped to deliver gas toboth nostrils simultaneously, the single cap being fed a gases streamthrough either a single or a double stem. ‘Nasal pillows’ in thisspecification should be read as covering at least these differentpossible designs, and not just the paired stalk and cap arrangementdescribed above. ‘Nasal pillows’ in this specification should also, ifappropriate, be taken to mean a nasal mask—for example, a silicone nasalmask fluidically connected to the gasket, the gasket in use beinglocated underneath the nostrils of a user and in front of the upper lipof a user. The nasal mask (‘nasal pillows’) would extend from thegasket, covering around at least part of the outside surface of the noseof a user and substantially sealing against the skin of a user so thatthe stream of heated humidified gases is delivered to the nare of theuser.

The features described above can be used individually or in anycombination in the pillows and interface of the present invention.

Lexicon

‘Supple’ or ‘flexible’ as these words are used in this specificationwith reference to e.g. the nasal pillows should be taken to mean thatthe item can be substantially and repeatedly deformed—e.g. by a userpinching, squashing or crushing it in their hand, with the itemreturning to its original shape with little to no plastic deformationoccurring. An item having a rectangular or square cross-section, with athickness of 1-2 mm, a width of e.g. 1 cm, and a length of 5 cm or more,formed from a ‘supple’ or ‘flexible’ material as it should be understoodin this specification, will, if held at one end, bend to an extenteasily appreciable to the naked eye—i.e. it will bend at least 2-3 mm.The most preferred materials having ‘supple’ or ‘flexible’ properties asthey should be understood within the context of this specification will,if formed in the manner referred to above, bend completely—that is,bending enough so that the unsupported end points substantially directlydownwards. If the material does not bend to an appreciable extent, thenit is a rigid or semi-rigid material for the purposes of thisspecification—see below. It should also be understood that ‘flexible’ isintended to mean a material that is soft, supple and flexible enoughthat an item formed with the dimensions outlined above (1-2 mm.times.10mm.times.50 min) could be rolled into a solid tube (i.e. with no central‘hollow’ portion), and when the tube is unrolled there would be littleto no plastic deformation of the material.

‘Rigid’ or ‘semi-rigid’ as it is used in this specification should beunderstood to mean that an item described in this manner can beelastically deformed, but that it would require application of anexternal force apart from gravity (i.e. more than its own weight) to doso—a ‘rigid’ or ‘semi-rigid’ item will not collapse or bend under itsown weight, in any orientation. It is noted that all items usuallydescribed as rigid do have a certain degree of elasticity, but theelastic limit will normally be reached before the elastic deformation ofthe rigid material is appreciable to the naked eye. Glass, for example,will shatter before the average person is able to appreciate that it haselastically deformed at all. An item having rectangular or squarecross-section, with a thickness of 1-2 mm and a length of up to 10 cm,formed from a ‘rigid’ or ‘semi-rigid’ material as it should beunderstood in this specification, will not bend to an extent easilyappreciable to the naked eye. As an example, the arms of the Fisher &Paykel Opus™ interface or the ResMed Mirage Swift™ II interface arearound 10-11 cm long and have a thickness of less than 1 mm. The arms ofthese devices are formed from a plastic having a rigidity so that theywill not bend under their own weight if held at one end, and for thepurposes of this specification can be considered to be ‘rigid’ or‘semi-rigid’.

‘Substantially vertically downwards’ as it is written in thisspecification should be interpreted as not necessarily meaningabsolutely vertical—an angle of 10-20 degrees or more off-vertical lieswithin the meaning of ‘substantially vertical’ as it is used in thisspecification.

It should also be noted that ‘downwards’, ‘outwards’, ‘inner’, ‘outer’,‘rear’, ‘front’, and similar terms as they are used in thisspecification refer to the mask being worn by a user who is standing up.For example, ‘inner’ and ‘rear’ refer to that side of the interfacenearest a users face in use. However, in use the interface is intendedto be used by a user who is asleep and will be lying on a bed, either ontheir back, front or side. The convention referred to above (a userstanding) has been adopted for ease of reference.

It should also be noted that the term ‘interface’ or ‘interfaceassembly’ as it is used in this specification refers to any combinationof the interface core section 11 (or 211, 311 or 411), the interfaceconduit 19 or supply conduit 190 (or both), and the headgear assembly12—that is, for the preferred embodiment, the term ‘interface’ couldrefer to the interface core section 11 with or without the headgearassembly 12, and with or without the supply conduit 19.

The terms ‘swivel’ and ‘rotate’ have their normal dictionarydefinitions. However, it should specifically be noted that as used inthis specification, ‘rotate’ means that the item turns around an axis orcentre point and movement is in a single plane. In contrast, ‘swivel’ asused in this specification should be taken to mean that the item iscapable of movement in more than one plane.

1.-20. (canceled)
 21. A nasal pillow section for use as part of anapparatus for providing a stream of gases to a user, the nasal pillowsection configured to be located in front of an upper lip of the userand below nostrils of the user when in use, the nasal pillow section,when viewed from the front and to one side of the nasal pillow sectionwhile being worn by the user in a standing position, comprising: apillow gasket having a gases aperture that receives the stream of gasesin use, the pillow gasket having a cylindrical portion that in use isaligned across a top lip of the user, the gases aperture beingpositioned at an axial end of the pillows gasket; nasal pillowsfluidically connected to the pillow gasket and configured tosubstantially seal against the nostrils of the user in use such thatsubstantially all of the stream of gases passes from the pillow gasketinto the nasal pillows and from the nasal pillows to the user; and alower inner surface of the pillow gasket having a straight planarsurface or a recessed portion that defines a concavity, the lower innersurface being user-facing.
 22. The nasal pillow section according toclaim 21, wherein the pillow gasket comprises, at a bottomforward-facing portion of the cylindrical portion, a slit that extendsalong a majority of a full length of the cylindrical portion.
 23. Thenasal pillow section according to claim 22, wherein the lower innersurface of the pillow gasket at a lower portion of the recessed portionand towards a lower portion of the pillow gasket in a direction awayfrom the nasal pillows curves rearwardly.
 24. The nasal pillow sectionaccording to claim 23, wherein the lower portion of the lower innersurface of the pillow gasket is rearwardly spaced apart from a lowerinner edge of the slit.
 25. The nasal pillow section according to claim22, wherein each of the nasal pillows comprises a stem, each stemcomprises a base, and the recessed portion of the lower inner surface ofthe pillow gasket extends from each base towards a bottom of the pillowgasket.
 26. The nasal pillow section according to claim 25, wherein eachof the nasal pillows comprises a cap, and each stem flares towards a topend where the stem merges with a bottom of the cap.
 27. The nasal pillowsection according to claim 25, wherein each of the nasal pillowscomprises a cap, and each stem has a partially cylindrical portion thatdefines a straight side.
 28. The nasal pillow section according to claim25, wherein a bridging platform extends between the stems of the nasalpillows.
 29. The nasal pillow section according to claim 28, wherein thebridging platform is stiffer than adjacent regions that extend around abase of each of the stems as well as the stems and the caps of the nasalpillows.
 30. The nasal pillow section according to claim 29, wherein thebridging platform is stiffer at least in part because of a greaterthickness.
 31. The nasal pillow section according to claim 27, whereinthe bridging platform comprises an indented profile and is configured tobe spaced apart from the upper lip.
 32. The nasal pillow sectionaccording to claim 25, wherein the lower inner surface has aforward-slope at an angle with respect to vertical with a lower edge ofthe lower inner surface being positioned further forward relative to anupper edge of the lower inner surface.
 33. The nasal pillow sectionaccording to claim 32, wherein the straight planar surface extendsbetween each base of the stems and a lower inner edge that defines atleast a portion of the slit.
 34. An interface for use as part of anapparatus for providing a stream of gases to a user, the interfacecomprising: a manifold section that includes a gases supply aperture,the gases supply aperture receiving the stream of gases, the manifoldsection connectable to a headgear assembly so that the interface is heldin position on a face of the user in use, and a nasal pillow sectionconfigured to be located in front of an upper lip of the user and belownostrils of the user when in use, the nasal pillow section, when viewedfrom the front and to one side of the nasal pillow section while beingworn by the user in a standing position, the nasal pillow sectioncomprising: a pillow gasket having a cylindrical portion that in use isaligned across a top lip of the user; nasal pillows fluidicallyconnected to the pillow gasket and configured to substantially sealagainst the nostrils of the user in use such that substantially all ofthe stream of gases passes from the nasal pillows to the user; and alower inner surface of the pillow gasket having a straight planarsurface or a recessed portion that defines a concavity, the lower innersurface being user-facing.
 35. The interface according to claim 34,wherein the manifold section and the cylindrical portion of the pillowgasket when assembled for use are aligned across the upper lip of theuser.
 36. The interface according to claim 35, wherein the manifoldsection is formed with a semi-rigid plastic and comprises a centralcross-brace body section, the central cross-brace body section beingpositioned between two end sections.
 37. The interface according toclaim 36, wherein the pillow gasket comprises, at a bottomforward-facing portion of the cylindrical portion, a slit that extendsalong a majority of a full length of the cylindrical portion.
 38. Theinterface according to claim 37, wherein each of the nasal pillowscomprises a stem, each stem comprises a base, the recessed portion ofthe lower inner surface of the pillow gasket extends from each basetowards a bottom of the pillow gasket, each of the nasal pillowscomprises a cap, each stem flares towards a top end where the stemmerges with a bottom of the cap, a bridging platform extends between thestems of the nasal pillows, and the bridging platform is stiffer thanadjacent regions that extend around a base of each of the stems as wellas the stems and the caps of the nasal pillows.
 39. The interfaceaccording to claim 38, wherein the bridging platform is stiffer at leastin part because of a greater thickness.
 40. The interface according toclaim 37, wherein each of the nasal pillows comprises a stem, each stemcomprises a base, the recessed portion of the lower inner surface of thepillow gasket extends from each base towards a bottom of the pillowgasket, each of the nasal pillows comprises a cap, each stem flarestowards a top end where the stem merges with a bottom of the cap, abridging platform extends between the stems of the nasal pillows, andthe lower inner surface has a forward-slope at an angle with respect tovertical with a lower edge of the lower inner surface being positionedfurther forward relative to an upper edge of the lower inner surface.